timeout docs: mention they're added in 1.2.9

docs/libssh2_session_get_timeout.3

@@ -13,5 +13,7 @@ return LIBSSH2_ERROR_TIMEOUT.
 By default libssh2 has no timeout (zero) for blocking functions.
 .SH RETURN VALUE
 The value of the timeout setting.
+.SH AVAILABILITY
+Added in 1.2.9
 .SH SEE ALSO
 .BR libssh2_session_set_timeout(3)

docs/libssh2_session_set_timeout.3

@@ -14,5 +14,7 @@ By default or if you set the timeout to zero, libssh2 has no timeout for
 blocking functions.
 .SH RETURN VALUE
 Nothing
+.SH AVAILABILITY
+Added in 1.2.9
 .SH SEE ALSO
 .BR libssh2_session_get_timeout(3)